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Android search with Fragments

android
search-engineering
fragments
action-bar
Anton ShumikhinbyAnton Shumikhin·Jan 29, 2025
TLDR

To implement search functionality with a Fragment, use a RecyclerView Adapter and a SearchView. Add a SearchView.OnQueryTextListener to the SearchView. Utilize the Adapter's filter method to manage the search logic. Here’s a hands-on code example:

public class SearchFragment extends Fragment { private YourAdapter adapter; @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View view = inflater.inflate(R.layout.fragment_search, container, false); SearchView searchView = view.findViewById(R.id.searchView); RecyclerView recyclerView = view.findViewById(R.id.recyclerView); recyclerView.setAdapter(adapter = new YourAdapter()); searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() { @Override public boolean onQueryTextChange(String newText) { // "Filtering like a rockstar!", the developer shouted. adapter.getFilter().filter(newText); return true; } // Implement onQueryTextSubmit, if you feel so inclined }); return view; } }

In this snippet, YourAdapter needs to manage the filter logic which corresponds to search queries. This code is engineered to provide you with ready-to-implement search functionality inside a Fragment.

Let's break down how to properly implement a search interface in Fragments as the Android system typically expects an Activity to handle search.

Integrating search in a Fragment's action bar

For adding search functionality to a Fragment's action bar, override onCreateOptionsMenu:

@Override public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) { inflater.inflate(R.menu.search_menu, menu); MenuItem searchItem = menu.findItem(R.id.action_search); SearchView searchView = (SearchView) searchItem.getActionView(); searchView.setOnQueryTextListener(queryTextListener); super.onCreateOptionsMenu(menu, inflater); }

Don't forget to call setHasOptionsMenu(true) in onCreate(). This signals that your Fragment has menu options. For Android-wide compatibility, use AppCompat v7 classes like AppCompatSearchView.

Using Loaders for advanced search management

Implement LoaderManager and CursorLoader to efficiently handle the search data life cycle in Fragments.

@Override public Loader<Cursor> onCreateLoader(int id, Bundle args) { // Initialize a loader with your query of choice } @Override public void onLoadFinished(Loader<Cursor> loader, Cursor data) { // Cursor is ready, let the adapter know! } @Override public void onLoaderReset(Loader<Cursor> loader) { // Cursor is being lazy, reset it! }

To refresh your data, make sure to initialize (initLoader) and restart (restartLoader) your loaders accordingly.

Tailoring Fragments for a custom search experience

Fragments offer great flexibility. For a custom search experience, consider the following:

  • Own Filter Logic: Write custom filter methods in your adapter.
  • Navigation Within Fragment: Swap search results within your current Fragment.
  • QM & LiveData: Use ViewModel and LiveData for responsive search handling.

Enriching your search for advanced use-cases

For richer applications requiring unified or complex search systems, consider these tips:

  • Unified Interface: Create an interface all searchable Fragments can implement
  • Fragment Communication: Use a shared ViewModel between Fragments and containers
  • Backstack Management: Manage fragment transaction history to handle changing search states

Adapting to varied contexts

Keep in mind the various contexts your Fragments may inhabit:

  • Use the correct context within your SearchView callbacks via getContext() or requireContext().
  • Inherit themes properly for consistent styling. When constructing SearchViews, remember to provide a suitable ThemedContext.